Mechanics Performance Analysis Of Portal Frame Structure Applied In Beam String

With the development of the economy,the emergence of new materials and the invention of new technology,the application of the new light steel structure is expanding.Now,a portal with a span of more than 30 meters is very common.Although portal rigid frame light steel structure has the advantage of light deadweight,dowel concise,convenient installation,seismic performance is good wait for an advantage,but also shortcomings such as low bearing capacity,stiffness,especially when the span increases,its bearing capacity and stiffness is very apparent,lost the superiority of portal rigid frame structure.In this paper,under the frame of door type's oblique beam increase wire ropes and poles,wire connection in the oblique beam end and prestress,the ordinary type of door rigid frame structure into a string type of door rigid frame structure.Due to prestressing in structure,not only can improve the bearing capacity and stiffness of the structure,also can increase the span of structure appropriately,is conducive to the development of light portal frame structure and the application.The structural performance of the portal beam is greatly improved after the structure of the string structure is adopted.From the stress Angle analysis,the normal door type rigid frame as the span increases,the inner force of the beam inner force is larger and larger,the requirement section also is larger and larger.For a string of door type rigid frame structure,due to the effect of prestress of the piece of string,to the oblique beam through poles imposed a upward force,the technical adjustment can improve the oblique beam internal force distribution,reduce the peak and oblique beam deflection,internal force and structure increase with the decrease of oblique beam section or span.At the same time,the tension in the string can also improve the pressure condition at the top of the portal column,which is beneficial to the design of the portal column.Theory of geometric nonlinear finite element analysis is applied in this article,combined with practical engineering apply,to a string of door type rigid frame light steel structure to analyze the structure performance of the system,compared the general frame and a string of door type gantry frame the advantages and disadvantages of two kinds of structure system,and a string of door type design parameters of frame structure are compared,and the optimized research work for a string of door type rigid frame structure is a certain reference value to the engineering application.